JPH0914800A - Refrigerating system - Google Patents

Abstract

PURPOSE: To provide a refrigerating system reducing the noise of a header and improving the reliability of a compressor in the system for allowing refrigerating machine oil and refrigerant to two-phase separate in the header. CONSTITUTION: The refrigerating system comprises a compressor 1, a condenser 2, an expansion mechanism 3, an evaporator 4, and a header 5 annularly connected, refrigerant and refrigerating machine coil having no or small mutual solubility with the refrigerant. The header 5 connects above the suction tube 6 of the compressor 1, and inserts the outlet tube 9 of the evaporator 4 and an oil return tube 10 from below. The tube 10 is opened at one end within the header 5, and connected at the other to the suction tube 6 of the compressor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system using a refrigerant and a lubricating oil of a compressor which has no mutual solubility in the refrigerant.

[0002]

2. Description of the Related Art In recent years, JP-A-5-157379 discloses a refrigeration system using a lubricating oil of a compressor in which the refrigerant and the refrigerant have no mutual solubility.

Hereinafter, the conventional refrigeration system will be described with reference to the drawings. FIG. 7A is a piping diagram of a conventional refrigeration system, and FIG. 7B is a sectional view of a header of the conventional refrigeration system. In FIGS. 7A and 7B, 1 is a compressor for compressing a refrigerant gas, 2 is a condenser for condensing the refrigerant gas discharged from the compressor, 3 is an expansion mechanism, 4 is an evaporator, Reference numeral 5 denotes a header in which the outlet side of the evaporator 4 is connected to the upper side and the suction side of the compressor 1 is inserted in the lower side, and 6 is a suction pipe which is inserted into the header 5 from the lower side of the header 5 and extends upward. .

Numeral 7 is a refrigerating machine oil which lubricates sliding parts in the compressor, which may be hard alkylbenzene oil, soft alkylbenzene oil having excellent low-temperature fluidity, polyalphaolefin, paraffinic mineral oil, naphthenic mineral oil or the like alone or It is a mixture, which has no or little mutual solubility with a refrigerant such as HFC134a containing hydrofluorocarbon as a main component. Reference numeral 8 is an oil return hole provided on the upper side surface of the suction pipe 6 inserted into the header 5.

Next, the operation will be described. The refrigerant discharged from the compressor 1 is condensed in the condenser 2, expanded under reduced pressure in the expansion mechanism 3, evaporated in the evaporator 4, and the refrigerant that cannot be completely evaporated in the evaporator 4 is stored in the header 5. Only the gas phase component is sucked into the compressor 1 through the suction pipe 6. At this time, the refrigerating machine oil 7 is discharged from the compressor 1 together with the refrigerant, flows in the piping, and reaches the evaporator 4.

The refrigerating machine oil 7 flows in the evaporator 4 together with the refrigerant that evaporates and evaporates, and is stored in the header 5 together with the liquid refrigerant stored in the header 5 or there. here,
Since the specific gravity of the refrigerating machine oil 7 is lighter than the liquid refrigerant and has no mutual solubility with the refrigerant, the refrigerant and the refrigerating machine oil 7 are separated into two phases, and the refrigerating machine oil 7 floats on the liquid refrigerant.

When the liquid level of the refrigerating machine oil 7 reaches the oil return hole 8, the refrigerating machine oil 7 is sucked into the suction pipe 6 through the oil return hole 8 and is sucked into the compressor 1.

[0008]

However, in the above-described conventional configuration, when the compressor 1 is turned on, turned off, or started, the liquid refrigerant that remains under the refrigerating machine oil 7 breaks through the refrigerating machine oil 7. Abnormal noise occurs due to sudden boiling evaporation.

Further, as the cooling progresses, the liquid level of the liquid refrigerant in the header 5 is located below the oil return hole 8 which is below the upper portion of the suction pipe 6, and the refrigerating machine oil 7 has a low temperature viscosity. Due to the rise, it becomes difficult to suck into the suction pipe 6 in the header 5, the amount flowing out from the suction pipe 6 becomes smaller than the amount flowing into the header 5, and the oil level is above the opening of the suction pipe 6. Located in.

At this time, since only the refrigerating machine oil 7 is sucked into the suction pipe 6 and no refrigerant is sucked into the suction pipe 6, the refrigerant supply amount to the compressor 1 becomes extremely small, and the refrigerating capacity is reduced, or the high compression is performed. Damage due to the ratio occurs.

Further, when the amount of liquid refrigerant staying in the header 5 changes due to the load change, the oil level of the refrigerating machine oil 7 changes, and the oil level rises and falls in the oil return hole 8, the refrigerating machine oil is transferred to the compressor 1. 7
Causes intermittent pulsation and abnormal noise, and when the amount of liquid refrigerant stays increases and stays near the upper part of the suction pipe, a large amount of liquid refrigerant returns to the compressor together with the refrigerating machine oil.
Liquid is compressed by the compressor and the compressor is damaged.

In view of the above problems, it is an object of the present invention to provide a refrigeration system in which the noise of the header is reduced and the reliability of the compressor is improved by suppressing the accumulation of refrigerating machine oil in the header.

[0013]

A compressor, a condenser, an expansion mechanism, an evaporator, a header, a refrigerant, and a refrigerating machine oil having no or little mutual solubility in the refrigerant, and the header is a compressor. The suction pipe of the machine was connected to the upper side, the outlet pipe of the evaporator and the oil return pipe were inserted from below, and one end of the oil return pipe was opened in the header and the other end was connected to the suction pipe of the compressor.

Furthermore, the oil return pipe has a smaller diameter than the suction pipe of the compressor. Furthermore, the outlet piping of the evaporator has a hole in the header below.

Furthermore, the oil return pipe has a micro hole in the lower part of the header. Further, a compressor, a condenser, an expansion mechanism, an evaporator, a header, a refrigerant, and a refrigerating machine oil having no or little mutual solubility in the refrigerant, the header,
The suction pipe of the compressor is connected to the upper side, and the other end of the oil return pipe whose one end is connected to the suction pipe of the compressor is inserted from below.The oil return pipe has a larger diameter than the outlet pipe of the evaporator, and the header The outlet pipe of the evaporator is inserted outside, and the inside of the header is opened below the outlet pipe.

[0016]

With the above-described structure, the refrigeration system of the present invention allows the refrigerating machine oil separated into two layers in the header to flow into the suction pipe of the compressor through the oil return pipe and stay in the header of the liquid refrigerant. It is possible to reduce the amount of refrigerating machine oil that accumulates and to reduce the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates. It can be reduced and the damage of the compressor can be prevented.

Further, since the header is connected to the suction pipe of the compressor above and the outlet pipe of the evaporator is inserted from below, the pipe diameter of the oil return pipe is thinner than that of the compressor. The amount of liquid refrigerant flowing into the compressor is reduced, and the reliability of the compressor can be improved.

Further, the liquid refrigerant that has accumulated under the refrigerating machine oil is returned to the evaporator side from the hole below the outlet pipe of the evaporator in the header to promote the evaporation of the liquid refrigerant, and the liquid refrigerant in the header It is possible to reduce the amount of stay and further reduce the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates, and reduce the inflow of the liquid refrigerant from the oil return pipe to the compressor due to excessive stay of the liquid refrigerant.

Further, by atomizing the liquid refrigerant from the lower minute holes in the header of the oil return pipe and returning it to the compressor from the suction pipe, the evaporation of the liquid refrigerant is promoted and the liquid refrigerant stays in the header. It is possible to reduce the amount of liquid refrigerant, further reduce the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates, reduce the inflow of liquid refrigerant from the oil return pipe to the compressor due to excessive retention of liquid refrigerant, and reduce the temperature of refrigerating machine oil Insufficient supply of refrigerant to the compressor due to evaporation inhibition of liquid refrigerant due to increase in viscosity can be reduced, damage to the compressor can be prevented, and a certain amount of refrigerant can be constantly returned to the compressor, so excess and deficiency of capacity can be reduced.

Further, the pipes to be inserted into the header are the oil return pipe and the outlet pipe of the evaporator to one oil return pipe having the outlet pipe therein, so that the header has two to one insertion port. In addition, the number of connections of the insertion portion can be reduced from two to one, and the number of manufacturing steps can be reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the refrigeration system according to the present invention will be described with reference to the drawings. The same components as those in the related art are denoted by the same reference numerals, and detailed description is omitted. FIG. 1 is a piping diagram of a refrigeration system according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the header shown in FIG.

In FIG. 1, the header 5 connects the suction pipe 6 of the compressor 1 to the upper side, and the outlet pipe 9 of the evaporator 4 and the oil return pipe 10 connected to the suction pipe 6 of the compressor 1 from below. Inserting.

In FIG. 2, the header 5 is internally open at the other end of the oil return pipe 10 whose one end is connected to the suction pipe 6 of the compressor 1 and at the outlet pipe 9 of the evaporator 4.

The operation of the refrigeration system configured as described above will be described below. As the load changes, the refrigerating machine oil 7 undergoes two-phase separation from a refrigerant mainly composed of hydrofluorocarbons such as HFC134a, which has no mutual solubility, and the specific gravity is lighter than that of the liquid refrigerant. It stays below, and the refrigerating machine oil 7 stays above.

At this time, the refrigerating machine oil 7 accumulated in the header 5 flows out from the oil return pipe 10 into the suction pipe 6 of the compressor 1 and returns to the compressor 1.

The liquid refrigerant that has accumulated below the header 5 evaporates and flows into the compressor 1 as a refrigerant gas through a suction pipe 6 of the compressor 1 connected above the header 5.

As described above, the refrigeration system of this embodiment is
The compressor 1, the condenser 2, the expansion mechanism 3, the evaporator 4,
In the refrigeration cycle in which the header 5 is connected in an annular shape and the refrigerant and the refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are connected, the header 5 connects the suction pipe 6 of the compressor 1 upward and evaporates. The outlet pipe 9 and the oil return pipe 10 of the container 4 are inserted from below, and one end of the oil return pipe 10 is opened in the header 5 and the other end is connected to the suction pipe 6 of the compressor 1. By returning the refrigerating machine oil 7 from the return pipe 10 to the compressor 1 through the suction pipe 6 to reduce the amount of the refrigerating machine oil 7 retained in the header 5, evaporation of the liquid refrigerant is promoted and refrigeration when the liquid refrigerant evaporates. It is possible to reduce the abnormal noise that breaks through the machine oil 7, and to reduce the shortage of the refrigerant supply to the compressor 1 due to the inhibition of the evaporation of the liquid refrigerant that accompanies the increase in the low-temperature viscosity of the refrigerating machine oil 7.

Next, a second embodiment of the refrigeration system according to the present invention will be described with reference to the drawings. In addition,
The same components as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 3 is a sectional view of a header according to a second embodiment of the present invention.

In FIG. 3, the oil return pipe 10 is the compressor 1.
Is thinner than the pipe diameter of the suction pipe 6. The operation of the refrigeration system configured as described above will be described below.

When the liquid refrigerant has accumulated excessively in the header 5 at the time of low load and at the time of starting and the liquid refrigerant reaches above the oil return pipe 10, the diameter of the oil return pipe 10 is the suction of the compressor 1. Piping 6
Because of the difference in pressure loss, a large amount of liquid refrigerant does not flow into the oil return pipe 10, and the liquid refrigerant that has flowed into the oil return pipe 10 mostly reaches the suction pipe 6 due to the difference in pressure loss. It is evaporated in 10 and is sucked into the compressor 1 as a refrigerant gas.

Further, even if the liquid refrigerant does not evaporate completely in the oil return pipe 10 and flows into the suction pipe 6, since it is not large, it can be vaporized in the suction pipe 6 up to the compressor 1 and the refrigerant to the compressor 1. Inhaled as gas.

As described above, the refrigeration system of this embodiment is
The compressor 1, the condenser 2, the expansion mechanism 3, the evaporator 4,
In the refrigeration cycle in which the header 5 is connected in an annular shape and the refrigerant and the refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are connected, the header 5 connects the suction pipe 6 of the compressor 1 upward and evaporates. The outlet pipe 9 of the container 4 and the oil return pipe 10 are inserted from below, and the oil return pipe 10 has one end opened in the header 5 and the other end connected to the suction pipe 6 of the compressor 1 Since the pipe diameter is smaller than that of the suction pipe 6, the oil return pipe 10
Since the refrigerating machine oil 7 is returned to the compressor 1 and the amount of the refrigerating machine oil 7 retained in the header 5 can be reduced, the evaporation of the liquid refrigerant is promoted and the abnormal noise that breaks through the refrigerating machine oil 7 when the liquid refrigerant evaporates is reduced. In addition to this, it is possible to reduce the shortage of the refrigerant supply to the compressor 1 due to the evaporation inhibition of the liquid refrigerant accompanying the increase in the low temperature viscosity of the refrigerating machine oil 7, and prevent the compressor 1 from being damaged.

Further, the amount of liquid refrigerant flowing into the compressor 1 can be reduced, and the reliability of the compressor 1 can be improved.

In the present invention, the diameter of the oil return pipe 10 is reduced to make a difference in pressure loss. However, the same effect can be obtained by increasing the pipe length or using a capillary pipe. Also,
It is preferable to determine the pipe diameter and length of the oil return pipe 10 so that the refrigerating machine oil 7 returns favorably without returning the liquid refrigerant to the compressor 1.

Next, a third embodiment of the refrigeration system according to the present invention will be described with reference to the drawings. In addition,
The same components as those in the first and second embodiments are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 4 shows the third aspect of the present invention.
3 is a cross-sectional view of the header according to the embodiment of FIG.

In FIG. 4, the outlet pipe 9 of the evaporator 4 in the header 5 is provided with a hole 11 below.

The operation of the refrigeration system configured as described above will be described below. The liquid refrigerant that has accumulated below the header 5 becomes mist from the hole 11 and flows into the outlet pipe 9 of the evaporator 4, evaporates, and again flows into the header 5 as a refrigerant gas, and flows above the header 5. From the connected suction pipe 6 to the compressor 1.

As described above, the refrigeration system of this embodiment is
The compressor 1, the condenser 2, the expansion mechanism 3, the evaporator 4,
In the refrigeration cycle in which the header 5 is connected in an annular shape and the refrigerant and the refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are connected, the header 5 connects the suction pipe 6 of the compressor 1 upward and evaporates. The outlet pipe 9 and the oil return pipe 10 of the container 4 are inserted from below, the oil return pipe 10 has one end opened in the header 5 and the other end connected to the suction pipe 6 of the compressor 1, and the outlet pipe 9 is Since the header 5 has a hole 11 at the bottom,
The evaporation of the liquid refrigerant is promoted by returning the liquid refrigerant accumulated under the refrigerating machine oil 7 through the hole 11 below the outlet pipe 9 of the evaporator 4 in the header 5 to the evaporator 4 side, and Refrigerating machine oil 7 when the amount of refrigerant retained is reduced and the liquid refrigerant evaporates
The noise breaking through can be further reduced.

Further, since the amount of the liquid refrigerant discharged from the hole 11 varies depending on the weight corresponding to the amount of the liquid refrigerant and the refrigerating machine oil 7 staying, the oil level of the refrigerating machine oil 7 in the header 5 is changed even when the load changes. Can be reduced, the amount of refrigerating machine oil 7 returned to the compressor 1 can be made constant, and the amount of outflow of the liquid refrigerant from the oil return pipe 10 to the suction pipe 6 at the time of excessive retention of the liquid refrigerant can be reduced. The durability and reliability of 1 can be improved.

Next, a fourth embodiment of the refrigeration system according to the present invention will be described with reference to the drawings. In addition,
The same components as those of the first, second and third embodiments are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 5 is a sectional view of a header according to a fourth embodiment of the present invention.

In FIG. 5, the oil return pipe 10 has a minute hole 12 provided in the lower part of the header 5.

The operation of the refrigeration system configured as described above will be described below. The liquid refrigerant that has accumulated in the lower portion of the header 5 is atomized from the minute holes 12 and is sprayed to the suction pipe 6 of the compressor 1 to promote evaporation and return to the compressor 1 as a refrigerant gas.

As described above, the refrigeration system of this embodiment is
The compressor 1, the condenser 2, the expansion mechanism 3, the evaporator 4,
In the refrigeration cycle in which the header 5 is connected in an annular shape and the refrigerant and the refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are connected, the header 5 connects the suction pipe 6 of the compressor 1 upward and evaporates. The outlet pipe 9 of the container 4 and the oil return pipe 10 are inserted from below, and the oil return pipe 10 has one end opened in the header 5 and the other end connected to the suction pipe 6 of the compressor 1 Has a minute hole 12 in the lower part of the header 5, the atomized liquid refrigerant accumulated in the lower part of the header 5 is atomized from the minute hole 12 and injected from the suction pipe 6 to the compressor 1 as a refrigerant gas. By returning, the evaporation of the liquid refrigerant can be promoted, the amount of the liquid refrigerant staying in the header 5 can be reduced, and the noise that breaks through the refrigerator oil 7 when the liquid refrigerant evaporates can be further reduced. Furthermore, since the amount of liquid refrigerant discharged from the minute holes 12 changes depending on the weight corresponding to the amount of liquid refrigerant and the amount of refrigerating machine oil 7 retained, even when the load changes, the oil level of the refrigerating machine oil 7 in the header 5 also changes. Can be reduced, the amount of refrigerating machine oil 7 returned to the compressor 1 can be made constant, and the amount of liquid refrigerant flowing from the oil return pipe 10 through the suction pipe 6 into the compressor 1 at the time of excessive retention of liquid refrigerant can be reduced. In addition, the durability and reliability of the compressor 1 can be improved, and a constant amount of refrigerant can be constantly returned to the compressor 1. Therefore, excess and deficiency of the capacity can be reduced.

Next, a fifth embodiment of the refrigeration system according to the present invention will be described with reference to the drawings. In addition,
The same components as those in the first, second, third and fourth embodiments are designated by the same reference numerals and detailed description thereof will be omitted. FIG.
FIG. 9 is a sectional view of a header according to a fifth embodiment of the present invention.

In FIG. 5, the oil return pipe 10 has a diameter larger than that of the outlet pipe 9 of the evaporator 4, and the outlet pipe 9 of the evaporator 4 is inserted into the oil return pipe 10 outside the header 5 so that the outlet pipe 9 The oil return pipe 10 having the pipe 9 is inserted from below the header 5. In the header 5, the outlet pipe 9 is open above the open part of the oil return pipe 10.

The operation of the refrigeration system configured as described above will be described below. Refrigerant and refrigerating machine oil 7 flow from the evaporator 4 into the header 5 through the outlet pipe 9,
Stay. Then, the refrigerating machine oil 7 accumulated on the liquid refrigerant is discharged from the oil return pipe 10 to the suction pipe 6 of the compressor 1. The liquid refrigerant evaporates and is discharged as a refrigerant gas through a suction pipe 6 connected above the header 5.

As described above, the refrigeration system of this embodiment is
The compressor 1, the condenser 2, the expansion mechanism 3, the evaporator 4,
In a refrigeration cycle in which a header 5 is connected in an annular shape and a refrigerant and a refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are provided, a compressor 1, a condenser 2, an expansion mechanism 3,
In the refrigerating cycle in which the evaporator 4 and the header 5 are connected in an annular shape and the refrigerant and the refrigerating machine oil 7 having no or little mutual solubility in the refrigerant are provided, the header 5 has the suction pipe 6 of the compressor 1 upward. And the suction pipe 6 of the compressor 1 at one end.
The other end of the oil return pipe 10 connected to is inserted from below, the oil return pipe 10 has a larger pipe diameter than the outlet pipe 9 of the evaporator 4, and the outlet pipe 9 of the evaporator 4 is inserted outside the header 5, Since it is opened in the header 5 below the outlet pipe 9, the refrigerating machine oil 7 accumulated in the header 5 is favorably returned to the suction pipe 6 of the compressor 1, thereby promoting evaporation of the liquid refrigerant and Can reduce the abnormal noise that breaks through the refrigerating machine oil 7 when it evaporates, and can reduce the shortage of the refrigerant supply to the compressor 1 due to the evaporation obstruction of the liquid refrigerant accompanying the increase in the low temperature viscosity of the refrigerating machine oil 7, thus damaging the compressor 1. Can be prevented.

Further, the pipes to be inserted into the header 5 are provided from the oil return pipe 10 and the outlet pipe 9 of the evaporator 4 to the outlet pipe 9
By having only one oil return pipe 10 that has inside, the insertion port of the header 5 can be reduced from two to one, and the connection of the insertion part can be reduced from two to one, which reduces the number of manufacturing steps. Can be reduced.

[0049]

As described above, the present invention comprises a compressor, a condenser, an expansion mechanism, an evaporator, a header, a refrigerant, and refrigerating machine oil having no or little mutual solubility in the refrigerant. , The header connects the suction pipe of the compressor to the upper part, the outlet pipe of the evaporator and the oil return pipe are inserted from below, and the oil return pipe opens one end in the header and the other end sucks the compressor. Since it was connected to the piping, the refrigeration oil that separated into two layers in the header and stayed on the liquid refrigerant was allowed to flow into the suction pipe of the compressor through the oil return pipe to reduce the amount of refrigeration oil retained in the header. It is possible to reduce the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates, and also to reduce the refrigerant supply shortage due to the evaporation obstruction of the liquid refrigerant accompanying the increase in the low temperature viscosity of the refrigerating machine oil, which damages the compressor. Can be prevented.

Further, since the oil return pipe has a smaller diameter than the suction pipe of the compressor, the inflow amount of the liquid refrigerant into the compressor is reduced and the reliability of the compressor can be improved.

Further, since the outlet pipe of the evaporator in the header has a hole at the bottom, the liquid refrigerant accumulated under the refrigerating machine oil is evaporated from the hole below the outlet pipe of the evaporator in the header. By returning to the side, the evaporation of the liquid refrigerant can be promoted, the amount of the liquid refrigerant staying in the header can be reduced, and the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates can be further reduced. The inflow of liquid refrigerant from the return pipe to the compressor can be reduced.

Further, since the oil return pipe has a minute hole in the lower part of the header, the liquid refrigerant accumulated in the lower part of the header is atomized from the minute hole and injected from the suction pipe to be compressed as a refrigerant gas. By returning to the machine, the evaporation of the liquid refrigerant can be promoted, the amount of the liquid refrigerant staying in the header can be reduced, and the noise that breaks through the refrigerating machine oil when the liquid refrigerant evaporates can be further reduced. Furthermore, since the amount of liquid refrigerant discharged from the minute holes changes due to the weight corresponding to the amount of liquid refrigerant and the amount of refrigerating machine oil retained, fluctuations in the oil level of the refrigerating machine oil in the header can be reduced even during load changes. The amount of refrigerating machine oil returned to the compressor can be made constant, and the amount of liquid refrigerant that flows into the compressor from the oil return pipe through the suction pipe at the time of excessive retention of liquid refrigerant can be reduced, making the compressor durable and reliable. In addition, the constant refrigerant can be constantly returned to the compressor, so that the excess and deficiency of the capacity can be reduced.

Further, a compressor, a condenser, an expansion mechanism,
An evaporator, a header, a refrigerant, and a refrigerating machine oil that has no or little mutual solubility in the refrigerant, and the header connects the suction pipe of the compressor to the upper side, and the oil whose one end is connected to the suction pipe of the compressor. Insert the other end of the return pipe from below, and the oil return pipe has a larger diameter than the outlet pipe of the evaporator, insert the outlet pipe of the evaporator outside the header, and open it in the header below the outlet pipe. Therefore, by changing the piping to be inserted into the header from the oil return pipe and the outlet pipe of the evaporator to one oil return pipe having the outlet pipe inside, the header insertion port is changed from two to one. It is possible to reduce the number of connections, and the number of connections of the insertion part can be reduced from two to one, which can reduce the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a piping diagram of a refrigeration system according to an embodiment of the present invention.

FIG. 2 is a sectional view of the header shown in FIG.

FIG. 3 is a sectional view of a header according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a header according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a header according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a header according to a fifth embodiment of the present invention.

7A is a piping diagram of a conventional refrigeration system, and FIG. 7B is a cross-sectional view of a header of the conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Expansion mechanism 4 Evaporator 5 Header 6 Suction pipe 7 Refrigerator oil 9 Outlet pipe 10 Oil return pipe 11 Hole 12 Micro hole

Claims (5)

[Claims] 1. A compressor, a condenser, an expansion mechanism, an evaporator, a header, a refrigerant, and refrigerating machine oil having no or little mutual solubility in the refrigerant, the header being the suction of the compressor. The pipe is connected to the upper side, the outlet pipe of the evaporator and the oil return pipe are inserted from below, one end of the oil return pipe is opened in the header, and the other end is connected to the suction pipe of the compressor. Refrigeration system. 2. The refrigeration system according to claim 1, wherein the oil return pipe has a smaller diameter than the suction pipe of the compressor. 3. The refrigeration system according to claim 1, wherein the outlet pipe of the evaporator has a hole downward in the header. 4. The refrigeration system according to claim 1, 2 or 3, wherein the oil return pipe has a minute hole in a lower part of the header. 5. A compressor, a condenser, an expansion mechanism, an evaporator, a header, a refrigerant, and refrigerating machine oil having no or little mutual solubility in the refrigerant, the header being the suction of the compressor. Connect the pipe to the upper part, and insert the other end of the oil return pipe, one end of which is connected to the suction pipe of the compressor, from below.The oil return pipe has a larger diameter than the outlet pipe of the evaporator and evaporates outside the header. A refrigeration system in which the outlet pipe of the container is inserted and opened in the header below the outlet pipe.